What is the appropriate course of action for a patient experiencing numbness on the face and left side for 1 week?

Immediate Emergency Evaluation for Suspected Stroke

This patient requires immediate emergency department evaluation to rule out acute stroke, which is a life-threatening condition requiring intervention within hours to prevent permanent disability or death. 1

Urgent Assessment Required

Facial and left-sided numbness for 1 week represents a HIGH RISK presentation that demands same-day comprehensive stroke evaluation. 1

• Patients presenting within 48 hours of unilateral numbness have a 10% risk of completed stroke within the first week, with highest risk in the first 48 hours 1
• Even though symptoms have persisted for 1 week, this still requires urgent stroke workup as the underlying pathology may be progressive or represent a transient ischemic attack with ongoing risk 1
• The combination of facial numbness with left-sided symptoms has a 72% probability of stroke when accompanied by facial weakness or speech disturbance 2, 1
• Isolated hemibody sensory loss alone still represents high stroke risk 1

Critical Initial Steps in Emergency Department

Immediate Physical Examination Priorities

Check bilateral radial pulses and blood pressure in both arms immediately to differentiate between stroke and acute arterial occlusion. 1, 3

• If pulse is absent or blood pressure unmeasurable on the left side, this indicates acute arterial occlusion requiring immediate vascular surgery consultation 1, 3
• A blood pressure difference >20 mmHg between arms confirms significant arterial compromise 3
• Assess the "6 P's" of acute limb ischemia: Pain, Pallor, Pulselessness, Paresthesias (numbness), Poikilothermia (cool limb), Paralysis 2, 3

Perform Cincinnati Prehospital Stroke Scale assessment: 2, 1

• Facial droop (have patient show teeth or smile)
• Arm drift (patient closes eyes and holds both arms straight out for 10 seconds)
• Abnormal speech (have patient say "you can't teach an old dog new tricks")
• If any one of these three signs is abnormal, the probability of stroke is 72% 2

Immediate Neuroimaging

Brain MRI with diffusion-weighted imaging is the preferred initial imaging modality to detect acute ischemic changes and must be performed immediately. 1, 4

• MRI differentiates ischemic from hemorrhagic stroke, which fundamentally changes treatment 1
• If MRI is unavailable, perform CT head without contrast to rule out hemorrhage 1, 4
• CT angiography or MR angiography from aortic arch to vertex must be included to evaluate carotid and vertebral artery disease 1, 4

Differential Diagnosis Considerations

Stroke vs. Trigeminal Neuropathy

The distribution and duration help differentiate stroke from trigeminal neuralgia or other facial pain syndromes:

• Trigeminal neuralgia presents with paroxysmal attacks lasting seconds to minutes with sharp, shooting electric shock-like pain, not continuous numbness for 1 week 2
• Continuous facial numbness for 1 week is more consistent with stroke, peripheral neuropathy, or structural lesion rather than trigeminal neuralgia 2
• Post-stroke pain presents as continuous ipsilateral dysesthesia with aching or burning quality 2

Peripheral Neuropathy Considerations

If metronidazole or other neurotoxic medications have been used long-term, consider drug-induced peripheral neuropathy:

• Metronidazole causes reversible peripheral neuropathy presenting as numbness and tingling in extremities, but this typically affects feet first and is bilateral 2
• Ciprofloxacin long-term use can cause peripheral neuropathy in addition to tendonitis 2
• However, unilateral facial and left-sided numbness is NOT consistent with typical peripheral neuropathy patterns 5

Treatment Based on Diagnosis

If Stroke or TIA Confirmed

Dual antiplatelet therapy (aspirin + clopidogrel 75 mg) should be initiated for the first 21 days in patients with symptomatic carotid stenosis not undergoing revascularization, followed by long-term single antiplatelet therapy. 1

• Carotid ultrasound must be performed to identify extracranial carotid stenosis >70% requiring carotid endarterectomy 1
• Comprehensive clinical evaluation and investigations by healthcare professional with stroke expertise must occur within 24 hours of first contact 1

If Acute Arterial Occlusion Confirmed

Immediate vascular surgery consultation for thrombectomy/embolectomy is required as outcome depends entirely on time to reperfusion. 1, 3

• Initiate anticoagulation (heparin bolus followed by infusion) unless contraindicated to prevent thrombus propagation 3
• Do NOT elevate the affected limb—keep at heart level or slightly dependent to maximize perfusion 3
• CT angiography from aortic arch to fingertips is the gold standard for identifying occlusion location and extent 3

Common Pitfalls to Avoid

Do not dismiss symptoms as "just numbness" or delay evaluation because symptoms have persisted for 1 week without progression. 1, 6

• Many patients delay seeking medical attention after TIA irrespective of correct recognition of symptoms 7
• Lack of knowledge of stroke symptoms is an important determinant of delayed presentation 8
• Fear of consequences, previous negative hospital experiences, or consulting family/friends first all result in delayed admission 8

Do not assume this is benign paresthesia or peripheral neuropathy without ruling out stroke first. 1, 5

• The combination of facial and unilateral body numbness strongly suggests central nervous system pathology 5, 6
• Peripheral neuropathy typically presents bilaterally and in a stocking-glove distribution, not unilateral face and body 5